kris396ss

Hey everyone, I could really use some help. The last leg of this build has been a nightmare, i've spend over 2k on tuning with 3 tuners and still can't really drive the car.
1996 Impala LSX B15 376 (stock out of the crate with the LS7 cam), LSA blower, 4l60e E67ECU T42 TCM, BP performance harness

Some back story: I had issues with my first trans (clogged filter, lots of metal, 3-4 clutch smoked after 200 miles and due to some mix up the ProTorque converter I had ordered through the builder ended up being wrong for my application) so after pulling it 3 times I finally went with a Performabilt level 3 and a circle D converter. Also went with a bigger cooler and flushed the lines.

Almost right away, I noticed that when the converter locked the car would violently buck. It didn't feel like the converter was unlocking, it felt like it was staying locked but the whole car would jerk somewhat violently if you tried to give it any throttle (picture a truck driver banging a gear in a big rig and bouncing, or driving a stick car where you shift too soon and let the clutch out too fast). Let it coast or give it enough gas to come out of lockup and it was fine. It didn't do it every time you drove the car, but when it did act it up it would do it almost every time the converter locked. It actually threw a P0741 code on the way to the tuner, but when I cleared the code it drove fine and lockup was smooth.

Tuner dyno tuned the car, charged me $800 but said he didn't feel comfortable with 4l60e's so he didn't touch any of the shift tables/trans stuff. The car drove like crap on the street, sluggish shifts, upshifting too early. Just felt like mush around town but great at WOT. The car made 660WHP but the tuner locked the converter manually on the dyno after I told him it was a single disk. He said it held fine though and didn't slip. Drove the car home and the jerking continued when the converter locked.

Found a remote tuner who said he thought he could fix my issues. Uploaded his tune and the converter problem was gone and the part throttle shift points/shifts felt way better. The car drove really good, not perfect as it still had a lurch coming to a stop but it was a huge improvement.

200 miles later, the problem came back. I took it for a cruise for about 30 miles and it drove fine. Parked it, started it up again 15 minutes later and the jerking began happening again every time the converter locked. Turned it off for 15 minutes to check the log, turned it back on to drive it home and it drove fine. Logged it when it was happening and you can see when the converter locks the RPM's begin bouncing between like 1200 and 1700. TCC pressure starts at zero and then tries to ramp up.
https://www.youtube.com/watch?v=JqJz...APerformabuilt said to max out the converter duty cycle
Tuner said he already did
Performabuilt said to move lockup to at least 45mph and move part throttle upshifts up by 10% below 50mph and it will feel much better
Still waiting on the tuner to reply to that



All of this got me a little worried and made me look back on two full throttle logs I took. The car spins like crazy so it's hard to feel what's going on, but I noticed some weird stuff in both logs. First thing I noticed was TCC line pressure dropped to 0 at the top of the shift. Then it looks like it shows the current gear selection randomly drop back into 2nd. Is that all normal from wheel spin? Here is a video of the pull, doesn't sound like it actually came out of gear to me but hard to tell.
Here is a video of that log



I also noticed this in another WOT log. Look for where my cursor points to, there is a dip at the middle of 3rd gear. I thought maybe it was wheel spin again but when I looked at the log it looked like line pressure dropped to zero just before the dip.

Now i'm worrying. Is this something that normally happens with wheel spin, or is it a sign of a trans issue/band slip?

performabuilt

iTrader: (25)

Bear in Mind when you are looking at DATA the 4L60E has no feedback so what you see is commanded numbers not actual numbers. The 4L60E has no pressure gauge in it.
So what you are seeing is what the PCM is commanding at any given moment and or a calculated number not actual pressure .
Now this is the Level 3 so because of mods we do you will feel the 3-2 downshift coming to a stop just FYI that part is normal for the unit.
Frank

kris396ss

thanks Frank, you have been a huge help throughout all of this. I haven’t met many trans builders who actually know enough about the computer side of things to help give tips to the tuner so that has been extremely helpful.

as for the 3-2 downshift, I don’t think that is what I’m feeling. I only say that because it will do it in second gear as well although it seems to be worse when slowing down with a locked converter. it happens JUST before the tires come to a stop. Almost feels like the idle hangs then surges.

what you say about the pressure makes sense. what about the gear selection? It kind of worried me seeing the log and seeing it bounce back and forth from 3rd back to 2nd then 3rd again at WOT but listening to the pull I can’t hear anything that sounds like it was slipping or coming out of gear. Just wondering if something electrical is acting up or if seeing that stuff is normal (especially when traction is very poor)

performabuilt

iTrader: (25)

The only thing I can think of in the gear selection assuming you mean part that shows manual position is electrical or the pan is sucking dry causing pressure drop ,But with the Pan we send on them and assuming the correct filter still in it and levels right that should not be possible.
The downshift clunk in manual second may actually be the 2-1 shift I was speaking on in the d3 or d4 positions when you feel it there it is the 3-2 and it will be abrupt with the level 3 and will feel very much like the downshift of a manual and clutch apply.
I would not be overly concerned with data logs as long as all feels normal They can be very confusing if your not sure what you are seeing or supposed to see.
I personally think your lockup issue is it coming into and out of lockup at way to low a speed in to high a gear causing thud and bucking like sensations this is why I suggested raising both the shift points at part throttle and lockup speed which is what I did to my own car but to a greater degree as My Impala is geared 3.08. I went up 20 percent .

kris396ss

Thanks Frank! I’ve been pretty paranoid about the level since the Lokar dipstick sucks (couldn’t fit a factory one). I verified the dipstick against the pan rail mounting surface and checked the fluid like 100 times lol. If anything I think I was a little high, as there was just a tiny bit of fluid dripping out of the vent and looked a little wet around that area under the car as if it sprayed out a little at some point. I drained maybe 1/8th qt out and now it’s right at the full mark, before it was just a tiny bit over.

you’re right about the logs. I’m still learning but I think I’m looking too deeply into them. I really wanted to just drop this car off at a tuner and not have to worry about it after spending years building it but I had so many bad experiences with tuning that I’m starting to think I better learn how to tune myself. I’d just rather not learn on a car I put this much money into lol

i told my tuner to try what you told me about raising the lockup speed and shift points. It really sounds like it might be the ticket. Something about this setup, either the cam or injectors or both don’t like idle at all so it almost makes sense the engine wouldn’t like high load just off idle at slow speed/rpm either. Just waiting on my tuner to get back to me on it.

performabuilt

iTrader: (25)

Where are you located ?

kris396ss

Suffolk county NY (Long Island)

performabuilt

iTrader: (25)

Not sure if its too far for your taste but if your looking for a do it all drop off tuner I would suggest RaceCrafers in Lancaster PA "BOB"

kris396ss

Thanks! At this point I just paid another $600 to another remote tuner who has improved it a lot up until the point where i experienced the converter jerking feeling again so I'm going to have to put my faith in him and see if he can sort it out. He seems pretty good, but my experience with tuners have been they give you one tune which is probably their pre-canned tune slightly modified for your setup and once that doesn't work all the support and help goes out the window. You end up paying a **** ton of money for something that probably took them an hour at most to do and when the real work starts they become difficult to get in touch with. Really hoping this won't be the case with my latest tuner, but if it is i'll be trailering the car up to lancaster before the season is over for sure. Really want to be able to drive this car a bit before the winter comes.

dlandsvZ28

IMO - you should talk to Circle D if they suggest that your converter can be locked on the dyno. I'm going to speculate that they will tell you NO. Nor should you lock the converter at WOT. Check your TCC WOT tables. Review pages 104 and 105 of Maslic's manual and CoolAid's guide as well.

I hope not, but your converter might already be toast. In the link below is a discussion about locking some converters on the dyno. While talking to Circle D you might ask if there is a way you or your tuner can make to check the condition of the converter.

https://ls1tech.com/forums/automatic...rter-dyno.html

Here is a link to a another thread where you posted about driveability.

https://ls1tech.com/forums/pcm-diagn...0e-tables.html

Are you relying totally on your tuner to make the changes necessary to achieve reasonable drive-ability or are you doing it yourself?

I've had at least 12 dyno tunes on my Procharged 1998 Z28 with a Yank converter and Performabuilt Level III 4l60e. Not a one of the tuners has ever touched the transmission tables and/or if they did after my complaint about drive-ability, all they would do is fiddle with the timing and idle.

In fact I just spent another $1300 on two dyno sessions. On the first of these last two dyno sessions the tuner flashed all of the stock 1998 transmission tables over the changes I had made to the shift tables. Why? I have no idea. On the second I told him to leave the tables alone and to NOT lock the converter on the dyno. He followed my instructions, but, I will NOT be taking my car back there again.

So why explain the above? IMO, like your experience, tuners will tune the engine, but completely ignore the drive-ability tuning that is necessary due to drastic cam changes over stock as well as significant drive-ability changes due to the higher stall speed if the stock TC has been replaced. It takes time to tune for drive-ability and if tuners can get by with sending you out the door and not tune for drive-ability they will. Period.

At $150 per hour - an $800 tune should get you at least 5 hours of work.

This is my suggestion. Tune your transmission yourself. That said, it takes hours and hours of reading and research as you learn to be able to do that. I posted in the other thread some good links. If you didn't download and study those resources and understand them then you will continue to search for tuners, continue to get bad results and in a worst case scenario ruin the converter.

If will take the time to read Maslic's manual. In it he explains in detail why and how to retune the transmission tables for driveability. You have a reasonably mild cam, so your's should be easier to tune. However, if you have a 4k stall perhaps not.

In his manual there is a modified shift table for the 4l65e transmission tuned for a cam that doesn't like to run at anything less than 1600 rpm. Read his explanation and you will understand why. You might start with that 4l65e table in his manual and then fine tune the table following the link to Cool Aid's where he essentially does the same thing.

Pay attention to "Torque Converter Clutch (TCC) Apply/Release Speed aka Lockup Speed in CoolAid's link"

https://ls1tech.com/forums/automatic...tm-w-pics.html

Here are two examples of what you need to pay attention to as well as others when you change the tables (doublecheck your tuner if he makes changes).

Some table values have to match - the WOT shift speed values compared to the Shift Speed VS TPS (throttle position) for example.
When setting part throttle apply speeds you can't expect to set apply speed to 45 mph while at the same time leave the release speed at 50 mph. Some suggest at least 4 mph difference between all apply and release speeds. TCC apply and release speeds work the same way.
When you let off the throttle the TCC should release. Period. You explain that it doesn't. Check the TCC release tables and also log TSP position voltage when you let off the gas. You might have to adjust TSP voltage or reset the TSP. The throttle cracker and follower tables can also effect the transition as you slow down and stop for a stoplight.

Read this about your DTC P0741 code

https://repairpal.com/obd-ii-code-p0741

As for finding the correct transmission dipstick and tube. Get one at a salvage yard. There are ten's of thousands of 4l60e's in salvage yards. You for sure want to make sure fluid level is correct.

hth

dlandsvZ28

With respect to your cam mild cam change. Your car won't drive like it does with a stock cam and as a result probably won't cruise at lower city blvd speeds at anything less than 15 to sixteen hundred rpm. So there's not much point in setting shift speeds in the part throttle table to upshift to a higher gears forcing the engine to run below 1600 rpm or so (logging will help to find that sweet spot).

When fine tuning the part throttle shift table there are two variables - shift speed and throttle position. You need to pay attention to both when making changes.

This scenario is one you might encounter.

Perhaps you have a loud exhaust (mothers with baby strollers don't like loud exhausts) and you have a higher than stock converter with more slip up to about 2800 to 3400 rpm. Your neighborhood cruise speed limit is 25- 30 mph. I don 't like to drive in my neighborhood with lot's of children over 20 mph for safety reasons and noise.

First gear in the 4l60e is 3.06 and 2nd gear is 1.63 (a pretty wide ratio between the two).

So when idling off from a stop in first gear the engine rpm jumps to 1200 rpm or so, the stall is slipping, and you are moving along in first gear perhaps as high as 16 -18 mph (making a lot of noise and not getting anywhere).

At the same time throttle position is just barely off the floor at 10 percent. Increasing throttle position doesn't help much because the converter still slipping. It would make sense to shift into 2nd but it doesn't because the commanded upshift at 10 percent throttle position to 2nd gear doesn't occur until 20 mph.

So what to do?

Lower the upshift from first gear to 2nd gear to a lower mph to command the transmission to shift to 2nd gear. Making this change drops engine rpm while at the same time increases mph because of the wide ratio between first and 2nd gear. The result is that you move along faster as a lower rpm and still stay under 25 mph.

Beware, however, when making changes as above. If you lower the upshift mph, you also need to lower the downshift mph. Obviously, you can't have the downshift mph higher than the upshift mph speed (you want at least a 4 mph difference).

The example above is entirely subjective and personal. What you like others might not like. So IMO you will need to do lots of logging and driving to fine tune drive-ability to what YOU want. This takes lots of time and a reason why a lot of tuners won't take the time. At $100 per hour or more drive-ability tuning gets very expensive. Stop, reflash, stop, reflash, stop reflash and so on.

CoolAids tuning guide also explains a scenario where he explains TCC lockup during highway cruise. Read it. It makes a lot of sense and for sure allows for better pass and go at 65 to 70 mph.

HTH

kris396ss

First, thank you for the advice! still have to read your second post but to answer a few things in the first: I was definitely upset with the tuner on that one. Every tuner I called local here didn't even seem to want me there when tuning it. I had to beg this one to call me before they did pulls but he only called me for the final few pulls and then only told me AFTER that he locked the converter manually. I built the car myself from the chassis up, nobody knows the car better than me and it's frustrating when tuners don't want you to be around when they are working. In any event, he claimed there was no slip and the converter held just fine. Not sure exactly how he could tell without an input speed sensor, but I guess it would also be obvious in the power curves? Regardless, the problem in my post was happening before the dyno tuning anyway when the trans only had a few miles and didn't seem to get worse after the dyno tune so I'm hoping it didn't affect anything.

As far as it locking at WOT, it was only those 4 or so dyno pulls. He was doing it manually and it's not locking at WOT normally.

As far as relying on my tuner, I am at this point only because my current tuner is still on the payroll so to speak so I didn't want to mess with anything that makes it harder for him to deal with. This whole ordeal really has given me a desire to learn tuning though. Honestly, if this were a budget build I would have from the start but my goal with this build was to make something daily driver/cross country reliable with late model street manners and I dumped a ton of money into it just to give me that peace of mind. I didn't want to mess anything up learning. I tune my procharged 70 challenger myself but it runs on a much more user friendly aftermarket engine management system, doesn't require any trans tuning (manual valve body) and I could care less if I burnt the motor down since I've been trying to kill it for years to go with a late model hemi LOL

As far as the first thread, I wanted the stock tables loaded to make sure I had a clean slate with the new transmission. With my first trans and tuner the car felt awful all around and trans temps kept going through the roof. Ended up finding a combo of mechanical issues between the trans and converter. When I got the new performabuilt trans and circle D converter in, the overall drivability still felt like crap the first drive but when I found my current tuner he cleaned that up right away and it now feels much better driving around town (aside from the converter lockup issue, of course). I'm at the point where if the converter issue is fixed, I think all is pretty much well.

I'm going to start reading through those how to's you posted as I'm sure it will be helpful to know and possibly start making minor adjustments on my own when I feel confident enough in my understanding of it. Thanks again for the info

kris396ss

Reading your second post, I 100% agree. I figured this car would need a bit of tweaking to get things just right with the cam/converter, although I purposely stuck with the "mild" LS7 cam that came with the long block and a mild 3200 converter in hopes that the car could drive somewhat like a factory car. The new tuner has made some big strides with that, but it's also difficult going back and forth by mailing logs and I'm sure the fine tuning could be accomplished easier if he were actually in the car driving it and tuning it. This is where the DIY aspect definitely comes into play, as it would be much easier (and cheaper) for me to learn some of this and fine tune it myself and tailor it to my own diving preferences.

Although the car feels way better with the new tuner's shift points during part throttle driving, I am wondering if some improvement can still be made by working on the idle. For some reason this car has been very hard for any of my 3 tuners to really smooth the idle out. I expected it to be a little rough with the overlap of the LS7 cam, but it always sounds like it's hunting...kind of an inconsistent surge. It's barely there, but definitely noticable. My first tuner said he thought it was the injectors (1050x) not liking idle, but when I switched to E85 with the added fuel requirements I figured that would have went away as the pulse width widened at idle but it made no difference. I thought maybe it was just the nature of this cam, but I just found a video of a C6 vette with an LSX B15 376 crate engine idling and his idle sounds perfectly smooth (I mean a little choppier than say a stock LS3 but no erratic hunting/surging). I'm wondering if whatever is causing that is also adding to the motor struggling at lower speeds/rpm's with the converter locked.

Just don't know where to begin for that. I've sprayed around the blower/block gasket with carb cleaner checking for vacuum leaks, checked plugs, it has all brand new GM coil packs, swapped the MSD's off for Granatelli wires, had the injectors flow tested and haven't found anything that would be causing it. AFR on my wideband fluctuates between 14.7 and 15.0 at idle. It's so minor most of the tuners dismissed it but it definitely doesn't seem like it should be there to me. I'll post a video but it's hard to even notice on video, but definitely noticeable in person (even my friends have pointed it out).

dlandsvZ28

IMO if you have to tell your tuner what to change, you might as well change it yourself.

Completely understand Maslic's section on transmission tuning. Same goes for CoolAids section on TTC. IMO I wouldn't mess with line pressures at all. Performabuilt installs a transkit which IMO is all you need. Some inexperienced tuners fool with pressure to the point they do more damage than good.

Your tuner should ride with you and should know exactly what to change when the TC starts to shudder and hunt at city blvd speeds. It's all about throttle position, shift speeds, shift timing, engine timing, weight of your car, rear end ratio, TC lockup, and stall rpm. If you are leaving the car with the expectation that he knows exactly what kind of drive-ability you expect, it's like playing telephone tag. It will take longer and cost more.

If the TC doesn't unlock when you let off the pedal - same thing. There are tables that need adjustment such as decel, follower, and cracker along with engine timing. Much of that is explained in Maslic's manual as well as his tutorials on his website. HP tuners has a tutorial to fix decel with an auto so when letting off the pedal coming to a stop everything transitions smoothly as the TC unlocks, engine rpm decreases to idle and the trans downshifts occur smoothly so when you stop the engine idles smoothly with no stumble attempting to stabilize (see Maslic tutorial also).

Tip: Always scan your tune before taking it to the tuner and save the file. Scan again when you get it back. Each change is accounted for in the tune and you can read it. Compare files and understand why the change was made and what if any result occurred. Make sure he understands that you want to know what he is doing. If he doesn't beware.

You might be surprised to learn what little has been done compared to the cost to make the change.

dlandsvZ28

Maslic has tutorials for idle tuning. There are four. Notice how smooth it idles. This crap from tuners that they all idle rough is BS.


With that stall and cam your car should idle just as smoothly as my C7 Z06. It's amazing how smooth it drives and idles with the 8 speed. And I'm getting just as close to smooth with my Procharged Z28 with a 227/234 TSP 370 (600 rwhp).

My issue now - is that I made the mistake of a higher stall (34 to 3600). High stall converters and more than mild cam specs don't cruise well at 45 mph. Too much slippage. So it takes hours and hours of logging to get there. A 2800 stall would make it easier and it would drive much much smoother.

You need to look at the BRAF table and also idle timing. Too much timing at idle creates more torque. You might have to back it off as Maslic does in his guide so you can blip the throttle and it transitions smoothly to idle with no stumble with AC on. There are tons of good tutorials explaining idle tuning.

Again - time consuming as you learn.

kris396ss

OK, so I had my tuner enter in what Frank from Performabuilt said (increase the lockup speed). I am not sure if he increased the shift points, or possibly they were already increased, because I didn't notice much difference there, but as far as the lockup goes I drove the car about 75 miles the other day and it felt fine. Didn't look at the logs yet but seemed like it was locking up closer to 50-55 instead of 40-45 it was doing before.

Under the conditions where it would begin to do the jerking before (usually very light throttle input accelerating with a slight load like a mild incline), I felt a little bit of a hiccup when it locked (not the normal feeling) but it smoothed out quick and didn't go into a violent fit like it was doing before.

Going to drive it more today, but hopefully that is one problem solved or at least greatly improved. In the mean time I am going to keep reading these tuning tutorials and start working on learning how to tweak these things myself.

My next battle will be with trying to get that hunting idle sorted out. As dlandsvz28 said, I really thought this cam in this long block would have the capability of idling pretty smooth without all the hunting/surging I get now. It's only little fluctuations but it is definitely noticeable. This was confirmed after finding a few videos of stock LSX B15 376 engines idling on youtube and not sounding as rough as mine does. I'm wondering how much of this might be from my 5" intake system. I went large thinking it would be best for power, but I have heard since that such a large intake tube creates some turbulance problems at lower air speeds like at idle. I have the MAF placed in a straight section of pipe, but it still is a massive intake tube.

Thanks again to everyone for the help.

RonSSNova

iTrader: (3)

Would be helpful if you could post the current tune and some of these log files.
This of course hoping it wasn’t tuned with HPT version 4.1X

I tuned one of those crate engines at the shop, IIRC, those are MAF only tunes from the factory.

That big intake tube slows the air down and that might be running at the bottom end of the MAF range.

HPT measures TCC slip, you should be able to add it to the data.
Factory tune unlocks it at WOT.

How much overlap in the cam?

performabuilt

iTrader: (25)

My surging idle issue were the aftermarket injectors I installed. I put stock back in a boom all fixed just a possibility.

kris396ss

I will give it a shot. Wasn't sure how to post an attachment like that here but I guess it would upload like any other attachment.

To answer a few questions, there was no factory tune with this one (it wasn't a GM connect and cruise package, just a long block) so I'm using an E67 ECU from a CTSV and T42 TCM, but the OS was modified somehow to use the 4 speed 4l60e. Not really sure how BP performance did that but the vehicle still shows up as a CTSV in HP tuners.

Unfortunately that is one of the issues we have had, the 4l60e does not have an input speed sensor so there isn't any way to measure TCC slip like you could with an 80e. That likely would have made diagnosing this a lot easier.

The cam is a GM LS7 cam. 210/230@.050 with a 120 LSA so it's big by GM standards to use in a 6.2L but not big at all in general. It's pretty much the same as an LS9 cam but I believe 1.5 LSA tighter, so I would assume it should be capable of idling as good or at least close to as good as a stock LS9. Mine definitely doesn't. It's not terrible but you definitely hear it hunting and surging a little up and down. It's not bad enough to make the car feel bad driving it but just annoying to listen to out of the car lol

Injectors are 1050x's so they are big injectors, but i'm making 660whp on E85 and I wanted a little room to grow. I had the injectors flow tested and they are all dead consistent with each other. My first tuner suggested that they just didn't like idle because of how big they were but when I switched from pump 93 to E85 the problem persisted even though I assume the pulse width would have widened a bit, so it made me think maybe that's not the issue.



As an update on the trans issue, I took the car out yesterday and drove it for about 100 miles. I only had the issue ONCE and it was nowhere near as bad as before. It was when I was was accelerating a little more aggressively (still very part throttle bit just a little more than usual cruising) onto a highway with a slight incline and the trans temp was a little higher, like around 200 after a pull or two followed by some lower speed stoplight driving. (stays around 175-ish normal driving, it will heat up fast when beating on it but come right back down when the converter locks and it's cruising or at a stop). When the converter locked I felt the RPM's pulsing slightly maybe 4-5 times and then it went away but it was nothing like before where the car would violently jerk and not accelerate. Raising the converter lockup speed definitely was a huge improvement. I have to check the log but i think it was locking up at around 50 or 55mph now.

RonSSNova

iTrader: (3)

You are correct about TCC slip. I’ve tuned too many Dodges!

I wrote a user defined math parameter for my TH400 Nova based on RPM and mph. Works well.

Correct on moving the lockup mph up, I had to do that as well in my vette. It was pissed off at 45 mph. I don’t let it lock in 3rd at all.

Your cam has no overlap at .050”

I’ve seen those injectors idle nicely at less than 1ms. So just needs some tuning there. Really long tube headers can confuse the O2 sensors, could be part of the problem.

Just use manage attachments. This site allows HPT files to be uploaded.

Got ya on the ecu etc!